Re: [PATCH] Revert "KVM: nVMX: Do not expose MPX VMX controls when guest MPX disabled"

From: Paolo Bonzini
Date: Fri Jul 22 2022 - 13:18:31 EST


On 7/22/22 17:27, Sean Christopherson wrote:
So revert it, at the potential cost
of breaking L1s with a 6 year old kernel.
I would further qualify this with "breaking L1s with an_unpatched_ 6 year old
kernel". That fix was tagged for stable and made it way to at least the 4.9 and
4.4 LTS releases.


Well, there _are_ people that use very old kernels and keep them up-to-date with fixes for only critical CVEs (for example by, ehm, paying my employer to do so). But still it's way way unlikely for them to be used as L1 in a nested setup, whether on their own hardware or in the cloud.

I pushed everything to kvm/queue, but depending on what you post it may be deferred to 5.21.

Paolo